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Objective: Phosphorylcholine (PC) is a structural component of Streptococcus pneumoniae (Spn) and nontypeable Haemophilus influenzae (NTHi), and is known to be associated with adherence through the platelet activating factor receptor (PAF-R). Furthermore, high PC expression is considered to be involved in Spn and NTHi virulence. In this study, we examined the influence of PC expression on the adherence of Spn and NTHi to epithelial cells in order to clarify the potential effectiveness of a vaccine targeting PC., Methods: Twenty-seven strains of Spn and twenty-two strains of NTHi were used, cultured overnight, and PC expression was evaluated by fluorescence activated cell sorting; the strains were divided into two groups: PC low expression (PC-low) and PC high expression (PC-high) groups. Bacterial adherence was then examined using Detroit 562 cells and BALB/c mice. Bacterial invasion was then examined in Detroit 562 cells., Results: The adherence of Spn and NTHi and invasion of NTHi in the PC-high group was significantly reduced by pretreatment with a monoclonal anti-PC antibody (TEPC-15), PAF-R antagonist (ABT-491), and PC-keyhole limpet hemocyanin (PC-KLH). However, such findings were not observed in the PC-low group., Conclusion: The present study suggests that PC is involved in the mucosal adhesion of Spn and NTHi, and the mucosal invasion of NTHi with PC-high strains, but not PC-low strains. These results suggest that a PC-targeting mucosal vaccine only affects PC-high Spn and NTHi strains and does not disturb commensal bacterial flora in the upper respiratory tract, which comprises nonpathogenic PC-low bacteria., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objective: To better understand the causes of the exacerbation of rhinitis medicamentosa (RM) induced by oxymetazoline (OMZ) or benzalkonium chloride (BKC), we examined the impact of pretreatment with OMZ or BKC on cultured human nasal epithelial cells. We also examined the effect of mometasone furoate (MF) on the cultured human nasal epithelial cells treated with OMZ or BKC., Methods: Cells of the human nasal epithelial cell line HNEpC were treated with OMZ or BKC, and the OMZ- and BKC-induced expression of histamine H1 receptor (H1R) mRNA was assayed using real-time polymerase chain reaction. In some experiments, 1.0×10(-5)M MF was added to the HNEpC cells for 24h before treatment with OMZ or BKC., Results: Treatment with OMZ slightly increased the expression level of H1R mRNA in HNEpC cells. This enhanced expression was not significantly reduced by pretreatment with MF. In contrast, treatment with BKC remarkably increased the expression level of H1R mRNA in HNEpC cells. In addition, this enhanced expression was significantly reduced by pretreatment with MF., Conclusion: These results suggest that the increased expression of H1R mRNA due to treatment with OMZ or BKC might be one of the factors underlying the exacerbation of symptoms in patients with RM and those complicated with allergic rhinitis. The concomitant use of a nasal steroid might reduce the exacerbation of symptoms caused by BKC, although there remains a risk of developing histamine hypersensitivity from the long-term use of a topical steroid-containing BKC., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Objectives/hypothesis: One of the major functions of vascular endothelial growth factor (VEGF) is increasing vascular permeability. We previously reported that VEGF is present in nasal secretions in rhinosinusitis, particularly in allergic rhinitis, and is hyperproduced immediately after antigen provocation. However, its function in nasal mucosa has not yet been investigated. This study was designed to estimate the increased vascular permeability by VEGF in nasal mucosa and to discuss its possible role in allergic rhinitis., Study Design: Prospective animal experiment., Methods: Hartley guinea pigs were used. Ethyl carbamate was injected into the abdomen for anesthesia, followed by intravenous injection of Evans blue into the femoral vein. Phosphate buffered saline, histamine, or VEGF was then applied to nasal cavities. Nasal mucosa was harvested after saline reflux from heart with phlebotomy by amputating the abdominal aorta. Tissue samples were soaked in formamide for 12 hours at 63 degrees C to extract dye exudates from nasal mucosa. To analyze vascular permeability, dye was quantified by colorimetry., Results: VEGF increased vascular permeability in nasal mucosa, and was more than 1 x 10(6) times more potent than histamine on the basis of molar units. Although increased vascular permeability by VEGF was not inhibited by histamine 1 receptor antagonist, it was markedly inhibited by anti-VEGF receptor antibodies., Conclusions: VEGF increased vascular permeability to a greater degree than histamine in nasal mucosa via a different pathway. Regulating VEGF may be a new therapeutic option for persistent nasal symptoms in allergic rhinitis.

We explore cellular and molecular mechanisms of nasal adjuvant of a combination of a plasmid encoding the Flt3 ligand cDNA (pFL) and CpG oligodeoxynucleotides (CpG ODN). The double DNA adjuvant given with OVA maintained prolonged OVA-specific secretory IgA (S-IgA) Ab responses in external secretions for more than 25 weeks after the final immunization. Further, both Th1- and Th2-type cytokine responses were induced by this combined adjuvant regimen. The frequencies of plasmacytoid DCs (pDCs) and CD8(+) DCs were significantly increased in nasopharyngeal-associated lymphoreticular tissue (NALT) of mice given the combined adjuvant. Importantly, when we examined adjuvanticity of pFL plus CpG ODN in 2-year-old mice, significant levels of mucosal IgA Ab responses were also induced. These results demonstrate that nasal delivery of a combined DNA adjuvant offers an attractive possibility for the development of an effective mucosal vaccine for the elderly.

Background: Vascular endothelial growth factor (VEGF), a pleiotropic polypeptide that mediates endothelial cell-specific responses such as induction of angiogenesis and vascular leakage, is hyperproduced in a variety of inflammatory disorders. In asthma, VEGF hyperproduction promotes mucosal edema by enhancing vascular leakage. However, in allergic rhinitis, details of the pathophysiological importance remain unclear. This study was designed to investigate and discuss the pathophysiological significance of VEGF in nasal secretions from perennial allergic rhinitis sufferers., Methods: Seven allergic rhinitis patients sensitized with house-dust mites and 12 chronic rhinosinusitis patients were enrolled. Nasal secretion VEGF was quantified and compared between groups. In allergic rhinitis cases, nasal lavage VEGF was estimated before and after the antigen provocation. Nasal gland VEGF was immunohistochemically investigated. VEGF messenger RNA (mRNA) levels in serous and mucous acini were analyzed by laser microdissection and light cycler-polymerase chain reaction., Results: VEGF levels in nasal secretions and nasal lavage from allergic rhinitis were higher than in nonallergic rhinosinusitis, after rather than before antigen provocation. VEGF mRNA expression was higher in serous versus mucous acini. These results are consistent with the immunohistochemistry results., Conclusion: In allergic rhinitis, there was significant VEGF production in serous acini, which was hypersecreted after antigen provocation. VEGF may play an important role in pathophysiology of allergic rhinitis.

To clarify the role of viral infection in otitis media, we intranasally inoculated mice with influenza A virus and examined histologic changes in the nasopharyngeal mucosa using a battery of lectins. Additionally, live Haemophilus influenzae or Streptococcus pneumoniae was injected into the nasopharynx after virus inoculation, and the clearance of bacteria from the nasopharynx was examined. Staining of the mucous blanket and epithelial cell surfaces in the nasopharynx with peanut agglutinin, succinyl wheat-germ agglutinin, and Bandeiraea simplicifolia agglutinin was significantly enhanced with intranasal virus inoculation when compared with that in control animals. The nasopharynx was moderately stained with Maachia amurensis agglutinin and wheat-germ agglutinin in control animals, and the staining was enhanced after virus inoculation. These findings were most remarkable 5 and 9 days after virus inoculation. The numbers of bacteria cultured from the nasopharynx were significantly increased when bacteria were injected 5 days after virus inoculation. These results suggest that an alteration in the glycoconjugate structure lining the nasopharyngeal mucosa caused by the influenza virus might be associated with the reduction in bacterial clearance.

To determine the efficacy of a mucosal vaccine against nontypeable Haemophilus influenzae (NTHi), mice were immunized nasally, orally, intratracheally, or intraperitoneally with NTHi antigen together with cholera toxin. Antigen-specific IgA antibody titers in nasal washes and the numbers of antigen-specific IgA-producing cells in nasal passages showed the greatest increases in mice immunized nasally. Cytokine analysis showed that interferon-gamma, interleukin (IL)-2, IL-5, IL-6, and IL-10 were induced by nasal immunization, suggesting that Th2- and Th1-type cells were generated. Furthermore, bacterial clearance of a homologous strain of NTHi from the nasal tract was significantly enhanced in the nasal immunization group. These findings suggest that nasal immunization is an effective vaccination regimen for the induction of antigen-specific mucosal immune responses, which reduce the colonization of NTHi in the nasal tract.

Recent studies have demonstrated that antigen-specific IgA immune responses in nasal cavity are induced by intranasal immunization with several antigens. However, the precise mechanisms regulating such immune responses are unclear. In the present study, mice were immunized intranasally with horseradish peroxidase (HRP) plus cholera toxin into the right nostril, and HRP-specific IgA immune responses were investigated. After the immunization, an enzyme-linked immunospot assay showed an increased number of anti-HRP IgA cells in the nasal mucosa. Histochemical staining demonstrated the presence of anti-HRP antibody-secreting cells, mainly in the nasal subepithelial layer. Interestingly, these cells were induced predominantly on the right nostril, where intranasal immunization was performed. These findings suggest that antigen-specific IgA antibodies in the nasal secretions were produced locally from antibody-secreting cells in the nasal mucosa and that IgA immune responses in the nose were compartmentalized. Furthermore, lectin histochemistry showed an accumulation of peanut agglutinin-positive cells in the nasal-associated lymphoreticular tissue, suggesting the development of germinal centers in the immunized animals.

We studied IgA immunoglobulins in nasal secretions in order to clarify mucosal immunity of the nasal cavity and paranasal sinuses during chronic nasal infection. Secretory IgA and serum type IgA of 165 samples of nasal secretions were analyzed quantitatively by use of electroimmunodiffusion techniques, and the specific antibody activity of secretory IgA against the M protein of Streptococcus pyogenes was investigated by use of enzyme-linked immunosorbent assay. Results show that although the secretory IgA content in nasal secretions was elevated in chronic sinusitis, its specific antibody activity against the M protein was lower than that in normal subjects. This evidence suggests that nonspecific secretory IgA antibodies are predominantly produced in chronic sinusitis, and that mucosal immunity preventing the adherence of bacteria is impaired in the diseased mucosa.

Reflectance spectrophotometry analysis has been applied to the human nasal mucosa in vivo to determine the objective parameters of the colors of the mucous membrane, as well as to study the hemodynamics and enzymatic activities related to respiratory chain metabolism in the nasal mucosa. In 24 normal subjects, there were three main spectral peaks: the peak at around 500 nm (PI), the smallest at 560 nm (P2) and the highest one at 660 nm (P3). In 28 patients with nasal allergy, spectral P3 shifted remarkably toward the shorter wavelength at around 640 nm, compared to that of normal subjects. Additionally, the increment of the absorption band at P2 was also observed. These phenomena could be seen in the nasal mucosa of the subjects after use of decongestant spray. Reflectance spectrophotometric analysis will serve as a non-invasive method of giving us useful information for a further understanding of the mucosal pathophysiology of the upper airway.